Structured surfactant compositions are pumpable compositions that exhibit shear-thinning viscosity and have the capacity physically to suspend water insoluble or partially water soluble ingredients. In many cases, the surfactant is present in such structured surfactant compositions in the form of packed spherulites, i.e., lamellar droplets, formed from an aqueous solution of the surfactant.
Structured surfactant compositions are useful in personal care applications, such as shampoos, body wash, hand soap, lotions, creams, conditioners, shaving products, facial washes, neutralizing shampoos, and skin treatments, in home care applications, such as liquid detergents, laundry detergents, hard surface cleansers, dish wash liquids, toilet bowl cleaners, and in other applications, such as oil field and agrochemical applications.
In some personal care compositions, such as, for example, children's shampoos, it important that the composition not irritate the eyes. In other applications, such as facial washes and compositions for sensitive skin, it is important that the composition does not irritate the skin. Ethoxylated nonionic surfactants, typically one or more ethoxylated alcohols or ethoxylated sorbitan esters, are typically used in such compositions because such ethoxylated nonionic surfactants are mild to the eyes and skin. However, higher (for example, with 3 or more ethylene oxide units per molecule) ethoxylated alcohols and ethoxylated sorbitan esters tend to be incompatible with structured surfactant systems in that such compounds tend to destroy the structure of such systems.
What is needed is a structured surfactant composition that provides typical structured surfactant properties, that is, shear-thinning viscosity and a capacity to suspend water insoluble or partially water soluble components and is mild to the skin and/or eyes.